Unless otherwise indicated herein, approaches described in this section are not prior art to the claims listed below and are not admitted to be prior art by inclusion in this section.
As per the Institute of Electrical and Electronics Engineers (IEEE) 802.11 specification, an access point (AP) needs to set the TIM bit in the TIM information element (IE) of the beacon frame for all client devices in power-save mode for which the AP has buffered data. In a dense environment with a significant number of client devices in power-save mode, however, this approach is not efficient especially when the AP has management protocol data units (MPDU) for a majority of the client devices in power-save mode. This is because, in a dense environment having a large number of client devices in power-save mode, issues such as high rate of frame collision, inefficient medium utilization and large power consumption tend to occur. For instance, upon receiving the beacon frame, the devices would contend for access to the medium at the same time to retrieve the buffered data, thus resulting in high frame collision rate. Additionally, due to high frame collision rate, back-off time and the number of retries increase for at least some of the devices contending for access to the medium, thus resulting in inefficient medium usage. Moreover, as beacon interval is not sufficient to serve all the devices in power-save mode, may devices may stay awake while receiving no data frame in a given beacon interval, thus leading to large power consumption.